A meta-analysis of 10 studies indicates that patients with MI who receive blood transfusions have a higher mortality risk, researchers reported in the Archives of Internal Medicine.
“Analyses of blood transfusion in MI revealed increased all-cause mortality associated with a strategy of blood transfusion vs. no blood transfusion during MI (18.2% vs. 10.2%) (risk ratio, 2.91; 95% CI, 2.46-3.44),with a weighted absolute risk increase of 12% and a number needed to harm of 8 (95% CI, 6-17),” Saurav Chatterjee, MD, division of cardiology, department of medicine, Brown University and Providence Veterans Affairs Medical Center in Rhode Island, and colleagues wrote in the study.
For the analysis, researchers conducted a systematic search of studies published between 1966 and 2012 comparing blood transfusion with no blood transfusion or a liberal vs. a restricted blood transfusion strategy. Studies of blood transfusion strategy in anemia associated with MI were abstracted as well as all-cause mortality rates at the longest available follow-up for the individual studies. Pooled effect estimates were calculated with random-effects models.
Blood transfusion was linked to a higher risk for mortality independent of baseline hemoglobin level, nadir hemoglobin level and change in hemoglobin level during the hospital stay, according to multivariate meta-regression. Risk for subsequent MI also appeared higher after blood transfusion (risk ratio, 2.04; 95% CI, 1.06-3.93).
“Of even greater concern was our finding of a significantly greater risk for myocardial reinfarction with blood transfusion," Chatterjee and colleagues wrote. "This finding seems to conform to recent findings of detrimental effects on platelet aggregation with blood transfusions. Overall, our findings are consistent with recent recommendations by the American Association of Blood Banks and in a prior Cochrane review for a restrictive blood transfusions practices among patients with acute coronary syndromes as expressed in the aforementioned guidelines by providing an updated meta-analysis on the topic in the absence of an adequately powered randomized trial.”
Disclosure: The researchers report no relevant financial disclosures.